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Attribute Member Keys - Pt II: Composite Keys - Page 6

The Collation
property affords us a way to specify the rules we wish to invoke for text data
string comparisons. While collation in general has multiple purposes, it
is often used to support the determination of whether the members of a given
pair of strings are alike or different. Several Sort Orders are also
available, with the Designator and Sort Order selections
defaulting to server settings.

14.
Click the
downwardarrowselector button to the right of the box labeled Collation
designator, to expose the collations available for selection, as partially shown
in Illustration 19.

Illustration 19: Available Collation Options (Partial View)

15.
Leaving the
settings Collation Designator dialog at theirpreviously established settings, click the Cancel
button to dismiss the dialog.

16.
Click the Format
label, just beneath the Collation property label, simply to rest it
there.

We
noted in Part I that
the Format property purports (via the Books Online and other documentation)
to allow us to specify - using Visual Basic (Format function) format
types - the conventions used in transforming numeric data to text, if such a
transformation is required. The reality is that the only member formatting
supported within the Unified Dimension Model (UDM) is the Trimming
setting that we discuss below. (We can, of course, employ named calculations
or column calculations (at the data source view level) within the cube
to achieve our formatting ends, as alternative approaches.

17.
Leaving the Format property blank, click the box to the
immediate right of the InvalidXmlCharacters label, just beneath the Format property, once again to enable the
downward-pointing selector button.

18.
Click the
downwardarrowselector button, to expose the three selection options
for InvalidXmlCharacters, as depicted in Illustration 20.

Illustration 20: Selection Options for InvalidXmlCharacters

TheInvalidXmlCharacters property is applicable in cases
where we expect data to be received in the XML format, and where we wish to
dictate the handling of such data. The values are explained in Table 2.

19.
Leaving the InvalidXmlCharacters property at its previously established
setting, click the MimeType label, just beneath the InvalidXmlCharacters property label, simply to rest it
there.

The MimeType property allows us to specify the
binary data type, where necessary to meet our needs.

20.
Leaving the MimeType property blank, click the box to the immediate
right of the Trimming label, just beneath the MimeType property, as before, to enable the
downward-pointing selector button.

21.
Click the
selector button, to expose the four options for Trimming selection, as shown
in Illustration 21.

Illustration 21: Trimming Property Value Selection Options

The Trimming property allows us to specify the
desired treatment of trailing spaces at the beginning / end of a string. As we see in Illustration 21 above, the options are self-explanatory.

22.
Click the OK
button to dismiss the DataItem Collection Editor.

NOTE: Please consider saving the
project we have created to this point for use in subsequent related articles of
this subseries, so as to avoid the need to repeat the preparation process we
have undertaken initially, to provide a practice environment.

23.
Select File
-> Save All to save our work, up to this
point, within the originally chosen location, where it can be easily accessed
for our activities within subsequent articles of this subseries.

24.
Select File
-> Exit to leave the design environment,
when ready, and to close the Business Intelligence Development Studio.

Conclusion

In this,
the second half of a two-part article introducing Attribute Member Keys,
we continued our recent group of articles focusing upon dimensional model
components, with an objective of discussing the associated concepts, and of
providing hands-on exposure to the properties supporting them. We
reviewed our initial introduction to the dimensional model and
summarized its role in meeting the primary objectives of business
intelligence. Next, we provided a brief overview of dimension attributes
in general, referencing a subseries of articles, within my Introduction to MSSQL Server Analysis Services
series, where we explore the properties underlying dimension
attributes in detail.

We continued our exploration of Attribute Member Keys.
First, we re-examined the three Attribute usage types (which we
initially discussed in Attribute Member Keys  Pt I:
Introduction and Simple Keys) that we can define within a containing dimension. We then
narrowed our focus to the Key attribute usage type (a focus that we
developed throughout Parts
I and II of this article), discussing its
role in meeting our business intelligence needs. We next followed with a discussion
of the role of the Key attribute from a technical perspective, including
its purpose within a containing dimension within Analysis Services.

We then reviewed the concepts of simple and composite
keys, narrowing our exploration in this half of the article to the latter.
We discussed differences between the two key types, and why composite keys
are sometimes required to uniquely identify attribute members. Finally,
we reviewed the Properties associated with a composite key, based
upon the examination of a representative dimensionattribute, Time,
within our sample UDM.